Rolling shutters typically include an array of horizontal slats which are articulated or linked such that the shutter can be rolled or wound onto a storage roller. The storage roller usually is contained within a housing that may be mounted above a window or door opening in a building. In use, the storage roller is rotated by a drive mechanism in opposite directions to roll and unroll the shutter thereby to raise and lower the shutter, respectively. As the shutter is lowered, opposite ends of the lowered slats are received and guided in side rails secured exteriorly to the building at respective sides of the opening to be opened and closed by the shutter. The guide rails usually are linear and retain the lowered shutter slats in generally coplanar relation parallel to the plane of the opening.
Known rolling shutters have provided with varying degrees of success one or more benefits including security against break-in, energy savings, protection against high winds, light control and noise abatement. On the other hand, known rolling shutters have had associated therewith one or more drawbacks including low aesthetic appeal, high cost and availability in only standard sizes or by special order.
One type of rolling shutter is characterized by extruded opaque plastic slats having hollow bodies of generally rectangular shape. Along the top edges of their bodies, the slats have upwardly projecting hook-like tongue members which hingedly interlock in channels formed in the lower edge portions of the slat bodies. The downwardly opening channels are partly closed to prevent pull-out of the tongue members while of sufficient depth to permit substantially full telescopic movement of the tongue members into the channels. By reason of such telescopic movement, the bodies of adjacent slats can be brought into edge-to-edge abutment for full closure of the shutter or slightly spaced apart to allow adjacent slats to pivot relatively for winding onto the storage roller.
When spaced apart as when suspended in front of the building opening, the bodies of adjacent slats would form a gap therebetween which would expose a stem portion of the hook-like tongue member. A common practice has been to punch a row of small and horizontally spaced apart slots into the stem portion to enable the passage of light and air between the relatively suspended slat bodies. The slots, however, weakened the hinge-like joint between adjacent slats, and the punching operation added to the cost of shutter manufacture. Also, the amount of light passed between the slat bodies was limited as was visual observation ability. Respecting the latter limitation, it was difficult if not impossible for a person standing a couple of feet inside the shutter to recognize through the shutter a person standing outside the shutter because of the limited view afforded by the small and horizontally spaced slots.
Known rolling shutters also have been provided with bending reinforcement in order to resist, for example, hurricane force winds. The bending moments caused in the slats by high winds usually are greatest at the middle of the side rail-supported rolling shutter and one approach to reinforcement has been to install a vertical bar as a center support for the rolling shutter. Another approach has been to insert strengthening rods inside hollow shutter slats, but known strengthening rods and their method of use have had associated therewith one or more drawbacks. For example, prior metal strengthening rods have had to be cut as by sawing if the length of the slats required adjustment to fit a particular width of a window. Such strengthening rods also added considerable weight to the rolling shutter. One known reinforcement was a metal rod having a back-to-back E-shape cross section. The rod was designed to frictionally fit into an intermediate cell formed by interior walls of the slat body.
Another undesirable feature of known rolling shutters has been the appearance of horizontal bands when sunlight is reflected off the outside surface of the rolling shutter. This banding effect gave the appearance that the buidling opening had horizontal bars extending thereacross which was not particularly attractive or aesthetically pleasing.